Fluid tank



FIG. 1 is a top-right perspective view of a fluid tank showing our new design;

FIG. 2 is a bottom-left perspective view thereof;

FIG. 3 is a top-right-back view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a left-side view thereof;

FIG. 7 is a right-side view thereof;

FIG. 8 is a top view thereof; and,

FIG. 9 is a bottom view thereof.

The broken lines in FIGS. 1, 2, 3, 8, and 9 depict portions of the fluid tank that form no part of the claimed design. 

CLAIM The ornamental design for a fluid tank, as shown and described. 